Screw and screw driver combination

ABSTRACT

The disclosure relates to the combination with a screw of a screwdriver containing laterally extending keys on the shank thereof affording a flex coupling between the screw head and the screwdriver with the keys of the driver removably fitting keyways of the cone-shaped head of the screw during use and materially compensating for misalignment as well as eliminating the bouncing of the blade of the driver from the screw slot, thus requiring only minimum pressure to maintain positive coupling.

United States Patent Barlow s] 3,675,694 July 11, 1972 [54] SCREW ANDSCREW DRIVER COMBINATION [72] inventor: John W. Barlow, 263 BrightonAve., San Francisco. Calif. 94129 [22] Filed: Jan. I3, 1971 [21] Appl.No.: 106,045

[52] U.S. Cl. 145/50 A, 85/45 [51 Int. Cl ..B25b 15/02 [58] Field ofSearch 145/50 A, 50 R; 85/45 [56] References Cited UNITED STATES PATENTS172,351 l/1876 Sloan ..85/45 422,307 2/1890 Libbey.. ....14$/50 A2.258.326 10/1941 Holt [45/50 A FOREIGN PATENTS OR APPLICATIONS1.027.698 4/1966 Great Britain ..8S/45 [/1964 Canada 145/50 A 1/1911Switzerland "145/50 R Primary Examiner-Robert C. Riordon AssistantExaminerRoscoe V. Parker. Jr. A!!orne \-Arlington C. White 57 ABSTRACTThe disclosure relates to the combination with a screw of a screwdrivercontaining laterally extending keys on the shank thereof affording aflex coupling between the screw head and the screwdriver with the keysof the driver removahly fitting keyivays of the cone-shaped head of thescrew during use and materially compensating for misalignment as well aseliminating the bouncing of the blade of the driver from the screw slot.thus requiring only minimum pressure to maintain positive coupling.

3Clailns,6 Drawing Flgures SCREW AND SCREW DRIVER COMBINATIONConsiderable attention has heretofore been devoted to the development ofimproved screws and screwdrivers, and a number of patents have issuedtherefor. Among these are US. Let. Pat. No. 1,476,653, directed to theformation of beveled surfaces upon opposite faces of the blade of ascrewdriver for engaging a correspondingly shaped nick or slot in thehead of the screw; US. Pat. No. 1,797,390 discloses a tapered blade onthe screw driver to provide strength to the blade yet allowing itsworking edge to be visible for facilitating its entry into the kerf ofthe screw, with a provided key on the bit entering a key-hole formed inthe screw; US. Pat. No. 2,160,244 discloses a specially formed screwheaddefining a socket to be engaged by a corresponding tapered body portionon the bit of the driver serving to guide and hold the driver securelycentered in the screw recess; US. Pat. No. 3 ,044,5 l3 provides for acentrally disposed hole in the center of the slot of the screw head.While many of these different types of screw drivers and screws haveentered the market, they have not met with great use because of the manydisadvantages in the combinations, principally in their tendencies tobounce apart while in endeavoring to drive the screw home to operativeposition, as well as while endeavoring to remove the screw. Thisparticular disadvantage causes others, such as ruining the slot in thescrew, damage to the bit of the screwdriver and frequently injuries tothe users. In many cases, the screws have been damaged beyond effectiveuse and must be replaced, and also the screwdriver. In some cases, whenattempting to remove prior types of screws, the surrounding portions ofthe work has splintered or become otherwise damaged requiring costlyreplacements. The present invention is directed to the provision of auniquely constructed screwdriver for engaging by flex coupling therewitha specially form screw whereby a combination is provided which obviatesall of the disadvantages of prior screw driver and screw combinationsand which does the job more effectively and more expeditiously.

A primary object of my invention is to provide a screw and screwdrivercombination which affords a flex coupling throughout 360 between thescrew and driver when in use. Another important object of the presentinvention is to provide a screw and screwdriver combination of theindicated nature which is additionally characterized by an increasedstrength in the flex coupling between the units in operation and thecapability of the connected units to maintain a steady pressure at thecenter of the screw head without bounce or slip-out or displacement ofthe driver in respect to the screw.

A still further object of my present invention is to provide an improvedscrew and screwdriver combination of the aforementioned characterwherein the uniquely constructed screw driver can be fitted and securedto the screw head during operation thereof for the entire period indriving the screw home as well as removing the same from the work.

A further object of the invention is to provide an improved screw andscrewdriver which in use and engagement with one another reduces to aminimum the destructive effects of misalignment, not accomplished in anyother screw and screwdriver combination heretofore.

A still further object is to provide a screw of improved constructionwhich is appreciably more efl'ective functionally with any or standardscrewdriver.

Other objects of the invention, together with some of the advantageousfeatures thereof, will appear from the following description of the bestmode contemplated by me of carrying out the invention and the manner ofmaking and using the same, as evidenced by an embodiment thereofillustrated in the accompanying drawings. It is to be understood thatvariations of such embodiment are included in the claims appendedhereto. Referring to the drawings:

FIG. I is a perspective view of the screwdriver component of a preferredembodiment of the invention.

FIG. 2 is a fragmentary sectional side elevational view of theembodiment of FIG. 1 taken on the 2-2 thereof and illustrating the bitof the specially constructed blade of the driver.

FIG. 3 is a fragmentary edge sectional elevational view, taken on theline 33 of FIG. I.

FIG. 4 is a perspective view of the screw component of the preferredembodiment of the invention.

FIG. 5 is a front elevational view, partly in section, of the embodimentof screw component shown in FIG. 4, taken on the line 5-5 of FIG. 4.

FIG. 6 is sectional detail taken on the line 6-6 of FIG. 5. In its bestmode, the combination screwdriver and screw of my present inventionpreferably comprises a pair of laterally extending keys on the blade ofa screwdriver disposed in opposed relation to one another on oppositesides of the blade, said keys being coextensive in length with theblade, together with an engageable screw formed with a cone-shaped basehaving a cross-slot in the head thereof for receiving the bit of theblade of the screwdriver as well as having keyways extending laterallyfrom the longitudinal center of said cross-slot and in opposed relationto one another; the bottoms of said keyways and the bottom of saidcross-slot tapering from the apex of the cone base on said head of saidscrew toward the outer ends of said keyways and said cross-slot.

In accordance with my invention, I provide a screwdriver which isgenerally designated by the reference numeral ll and which includes ahandle 12 of generally cylindrical shape but preferably tapering towardits outer extremity, and also includes a blade 13 preferably formed orcast integrally with the handle 12 and which terminates at its outerextremity with a straight bit 14 of predetermined width for engaging thekerf of a screw. The blade 13 of the screwdriver 11 is so fashioned asto provide thereon a pair of keys l6 and 17, which, as shown, extendlaterally on opposite sides of the blade and longitudinally of the blade13 from the bit 14 to the handle 12. Preferably, the keys I6 and 17 arearranged on the blade 1 3 so as to oppose one another midway of thelength of the bit 14 or width of the blade. The screwdriver II, in itsentirety, can be cast from a suitable spring steel or steel alloy stockto insure life-time durability since it is re-sharpenable, or the handle12 thereof can be fabricated from a hard wood, or from plastic materialand press-fitted or otherwise permanently secured to the blade 13. Theprovision of the keys l6 and 17 on the blade lends great strengththereto and this resists distortion or snapping apart upon theapplication of external force, such as from the driven shaft of a motorto which it may be detachably connected.

As particularly illustrated in FIGS. 4 and 5 of the annexed drawings, Iprovide a specially formed screw 2I for cooperation with the uniquelyconstructed screw holder 11 in fastening elements of a work together,both not shown, as well as for loosening the screw and removing the samefrom the work, when desired. The screw 2] comprises a shallow cone base22 which merges into a threaded shank 23 of conventional form consistingof a cylinder of wood or metal having a helical ridge winding around it.While a wood screw is illustrated with standard tapering spiral thread,the shank 23 can be so threaded as to provide a metal screw for holdingmetal parts together. In addition to the customary cross-slot 24 in acircular top with circumferential rim 25 which cross-slot 24 is ofgreater depth adjacent to the rim 25 than prior screw slots because ofthe tapering of the slot in conformity with the cone base 22, I providein the head of the base 22 a pair of opposed key-ways 26 and 27 whichextend from approximately the longitudinal center of cross-slot 24 andfrom opposite sides of such crossslot. Preferably, and as hereinabovestated, the body of the head 22 of the screw 21 is formed in the shapeof a shallow cone with its apex 28 at the center of the cross-slot,considered longitudinally and transversely. The shallow coneconstruction of the head 22 of the screw results in a tapering ofone-half of the bottom of the cross-slot 24 from the center thereof orapex 28 of the shallow cone in one direction to and through theperimeter 25 of the top of the head, as well as a tapering of the bottomof cross-slot 24 in the opposite direction to and through the perimeter25 at a diametrically opposite point from the bottom one-half ofcross-slot 24 above mentioned. Similarly, the cone-shaped head 22provides for a tapering of the bottoms of each of the keyways 26 and 27from the apex 28 of the shallow cone head to the end wall of eachkeyway; such keyways 26 and 27 merging said cr'ris-slot'i 'tenddib beincluded in the appended claims.

at their inner ends.

This construction of the head 22 of my improved screw 21 afl'ords, whenthe screwdriver is engaged with the screw, a flex coupling therebetweenso that throughout a 360 turning of the screwdriver 1 l in driving thescrew 21 home into the work as well as in removing the screw from thework there is no likelihood of the screwdriver bouncing out of thecross-slot 24 or out of the keyways 26 and 27 as there is virtually alocking of the straight bit 14 of the blade [3 of the driver as well asthe keys 16 and 17 thereon with, respectively, the cross-slot 24 of thescrew and the keyways 26 and 27 thereof, even allowing for the usualtilting of the screwdriver in respect to the screw during theseoperations of fastening and unfastening of the screw: into and from thework. Moreover, by virtue of the cooperative interfitting between thebit of the screwdriver It and the cross-slot of kerf 24 of the screw 21,which cross-slot is of sufficient depth to receive the bit 14, as wellas between the keys to and 17 of the screwdriver and the keyways 26 and27 of the screw head 22, which likewise of sufficient depth anddimensions to receive the keys l6 and 17 of the driver 11, thelikelihood of misaligning the two components, that is, the screw andscrewdriver, when driving a screw home or unfastening the same, isreduced to a minimum. It seems evident, also, that there is littlelikelihood of tearing of the side walls of the cross-slot 24 or of thekeyways 26 and 27 during turning operations through the complete turningcircle, thus prevention of damage to screws and screwdriver is virtuallyeliminated and losses in the stocks of screws are avoided.

It is to be understood that variations in shapes of the keys on thescrewdriver and the keyways in the screw head are inlclaim:

l. A screw and screwdriver combination for flex coupling with oneanother to detachably secure portions of a work together; said screwcomprising a head having a cross-slot therein, a cone-shaped baseintegral with and underlying said head with the apex of said cone at thelongitudinal center of said cross-slot and with the bottom of saidcross-slot tapering outwardly in opposite directions from the apex ofsaid coneshaped base, and a pair of keyways in said base extendingoutwardly from opposite sides of said cross-slot with their bottomstapering outwardly therefrom; said cross-slot and said keyways beingadapted to removably receive a screwdriver comprising a handle, a bladeon said handle, a bit on the outer extremity of said blade for removablyfitting said cross-slot of said screw and engagingly rotating the same,and a pair of keys on opposite sides of said blade for removably seatingin said keyways of said screw to effect a flex coupling therewith duringrotation of said screw in driving the same into the work and removingthe screw from the work.

2. A screw and screwdriver combination as set forth in claim I whereinsaid cross-slot of said screw crests at the longitudinal and transversecenter thereof as the apex of the cone of said cone-shaped base fortiltably receiving and holding the bit of said screw-holder.

3. A screw and screwdriver combination as set forth in claim 1 whereinsaid keys on said blade of said screwdriver are flex coupled with saidkeyways and applied pressure of said screwdriver onto said screw is uponsaid cross-slot of said screw at the apex of said cone-shaped base.

1. A screw and screwdriver combination for flex coupling with oneanother to detachably secure portions of a work together; said screwcomprising a head having a cross-slot therein, a coneshaped baseintegral with and underlying said head with the apex of said cone at thelongitudinal center of said cross-slot and with the bottom of saidcross-slot tapering outwardly in opposite directions from the apex ofsaid cone-shaped base, and a pair of keyways in said base extendingoutwardly from opposite sides of said cross-slot with their bottomstapering outwardly therefrom; said cross-slot and said keyways beingadapted to removably receive a screwdriver comprising a handle, a bladeon said handle, a bit on the outer extremity of said blade for removablyfitting said cross-slot of said screw and engagingly rotating the same,and a pair of keys on opposite sides of said blade for removably seatingin said keyways of said screw to effect a flex coupling therewith duringrotation of said screw in driving the same into the work and removingthe screw from the work.
 2. A screw and screwdriver combination as setforth in claim 1 wherein said cross-slot of said screw crests at thelongitudinal and transverse center thereof as the apex of the cone ofsaid cone-shaped base for tiltably receiving and holding the bit of saidscrew-holder.
 3. A screw and screwdriver combination as set forth inclaim 1 wherein said keys on said blade of said screwdriver are flexcoupled with said keyways and applied pressure of said screwdriver ontosaid screw is upon said cross-slot of said screw at the apex of saidcone-shaped base.